Five-Dimensional Black Hole May Break Down Einstein's Theory of General Relativity

Scientists have shown just how a bizarrely shaped black hole could cause Einstein's general theory of relativity to break down. However, this black hole would only exist in a universe with five or more dimensions.

In this latest study, the researchers successfully simulated a black hole shaped like a very thin ring, which gives rise to a series of "bulges" connected by strings that become thinner over time. These strings eventually become so thin that they pinch off into a series of miniature black holes, similar to how a thin stream of water from a tap breaks up into droplets.

Ring-shaped black holes were "discovered" by theoretical physicists in 2002. However, this is the first time that their dynamics have been successfully simulated using supercomputers. Should this type of black hole form, it would lead to the appearance of a "naked singularity," which would case the equations behind general relativity to break down.

General relativity underpins our current understanding of gravity. In part, the theory tells us that matter warps its surrounding spacetime, and what we call gravity is the effect of that warp. In the 100 years since it was published, general relativity has passed every test thrown at it. One of its limitations, though, is the existence of singularities.

A singularity is a point where gravity is so intense that space, time and the laws of physics break down. General relativity predicts that singularities exist at the center of black holes, and that they are surrounded by an event horizon where the gravitational pull becomes so strong that escape is impossible.

"The better we get at simulating Einstein's theory of gravity in higher dimensions, the easier it will be for us to help with advancing new computational techniques-we're pushing the limits of what you can do on a computer when it comes to Einstein's theory," said Saran Tunyasuvunakool, one of the researchers, in a news release. "But if cosmic censorship doesn't hold in higher dimensions, then maybe we need to look at what's so special about a four-dimensional universe that means it does hold."